# SetCapabilityValue

**URL:** <https://community.homey.app/t/setcapabilityvalue/16492>\
**Category:** Developers\
**Tags:** z-wave\
**Created:** [August 5, 2019, 9:26pm UTC](https://community.homey.app/t/setcapabilityvalue/16492 "2019-08-05T21:26:03Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jan\_Erik\_Ankervig\_Tr](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/jan_erik_ankervig_tr/32/12456_2.png) [@Jan\_Erik\_Ankervig\_Tr](https://community.homey.app/u/Jan_Erik_Ankervig_Tr)\
**Post date:** [August 5, 2019, 9:26pm UTC](https://community.homey.app/t/setcapabilityvalue/16492/1 "2019-08-05T21:26:03Z")

</div>

Hi,

I’m trying to create a script that turns on all lights in a zone with a delay of x milliseconds between each light. I use one dimmer pr light (still cheaper than DALI).  
I then noticed that when calling the setCapabilityValue method, it only updates once the script returns, thus, all lights turn on at the same time.

Is there a way to actually execute the setCapabilityValue prior to script completion?

PS: The reason for this script is because the delay in a standard flow card is set to seconds as it’s lowest input (integer). I would like to go bellow that.

My code looks like this:

```
// This script turns on all lights in the Garden zone in a cascade with
// the time of delayInMilliseconds in between each light.
var delayInMilliseconds = 250;
let devices = await Homey.devices.getDevices();
let zones = await Homey.zones.getZones();

for(var i in zones)
{
    if(zones[i].name == 'Garden')
    {
        var gardenId = zones[i];
        console.log('Garden found in id: ', zones[i].id);
    }  
}

for(var i in devices)
{
    if(devices[i].zone == gardenId.id)
    {
        console.log(devices[i].name);
        devices[i].setCapabilityValue('onoff', true);
        sleep(delayInMilliseconds);
    }
} 
return true;

function sleep(ms) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > ms){
      break;
    }
  }
}
```

---

<div class="post-metadata">

**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [August 6, 2019, 6:47am UTC](https://community.homey.app/t/setcapabilityvalue/16492/2 "2019-08-06T06:47:35Z")

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`setCapabilityValue` is asynchronous, so you have to wait for it to complete before continuing the loop:

```auto
await devices[i].setCapabilityValue('onoff', true);

```

Also, your `sleep` function won’t work (properly) because it blocks the event loop. You need to create an async version for it:

```auto
function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms))
}
// to use, you need to use `await` as well:
// await sleep(delayInMilliseconds);

```

And lastly: if you’re getting syntax errors regarding to use of `await`, you need to wrap your entire script in an IIFE that marks the top-level function as `async`, allowing you to use `async` within its block:

```auto
void async function() {
  ... your script here ...
}();

```

---

<div class="post-metadata">

**Author:** ![Rocodamelshekima](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/rocodamelshekima/32/8209_2.png) [@Rocodamelshekima](https://community.homey.app/u/Rocodamelshekima)\
**Post date:** [August 6, 2019, 7:23am UTC](https://community.homey.app/t/setcapabilityvalue/16492/3 "2019-08-06T07:23:14Z")

</div>

Moved to developers.